This invention relates to a navigation system for providing route guidance by searching for a route from a present position or starting point upon input of a location such as a destination or transit point.
When any desired location is entered to set a destination or transit point in a vehicular navigation system installed in an automotive vehicle, entry by telephone number has been proposed as a form of location entry in addition to entry by code, entry by map coordinates and entry of registered location by retrieval according to genre. An example of an apparatus for entering a location by setting a destination by telephone number is disclosed in the specification of Japanese Patent Application Laid-Open No. 64-10383. According to this apparatus, a data base in which locations are stored in correlation with telephone numbers is prepared in advance. When a particular location has been retrieved, the name and address of the subscriber are displayed so that the entered location can be verified.
An example of a data base which can be used for such entry of telephone numbers is one in which telephone numbers and the names and addresses of the subscribers are registered upon being entered from a classified telephone directory. If the subscribers are retailers, statistically up to 30% of the names of the traders concerned change on an annual basis, depending upon the type of business. This means that if telephone numbers are entered when setting locations, there will be occasions where subscriber-name data corresponding to a telephone number will not always be the latest data when the subscriber name, which has been registered by its telephone number, is displayed for verification of the entered location. In such case the entered location will be different from the stored location. A problem which arises as a consequence is that the driver will not be able to tell whether the wrong location was selected because of a change in the telephone or the wrong telephone number was entered. It is required that the data be updated to the latest available data. Further, consideration has been given to increasing the verification information by simultaneously displaying the address in addition to the name of the subscriber in order to improve accuracy. When registered locations are increased in number, however, this results in too much data, which can no longer be registered in memory. This also makes updating a laborious task.
As example of a navigation system equipped with a location registration function is disclosed in the specification of Japanese Patent Application Laid-Open No. 5-131573. This apparatus is such that in a case where a location such as a destination or transit point is entered, a location once entered is registered in the system, whereby the entry operation is facilitated by enabling use of this registered location the next time.
This apparatus is such that in order to identify a registered location if the location has indeed been registered, input information is registered as the location name in a case where the registration has been designated by a designating input of character information. In a case where the registration designation has been made by selection from a displayed list without relying upon a designating input of character information, date-and-time information is registered as the location name. In a case where date-and-time information is registered as a location name, however, an inconvenience encountered is that one cannot tell which location this information belongs to when it is viewed subsequently. Though a place name desired to be registered as a location can be entered by characters according to this system, a problem of is that the characters must be entered one at a time. Thus, it is not necessarily easy to register and call locations with the conventional apparatus.
In order to solve these problems, consideration has also been given to a method of registration carried out by automatically writing in an address which includes a location registered by the system as a registered location name. However, even in a case where registration of a location is performed by selecting a the name of a facility or the like, if, say, ".sub.-- -- Golf Course" is selected and registered, the golf course is registered as the address which includes the location of the golf course and is not registered as the name of the golf course. This means that if the driver cannot remember the address that corresponds to the registered name of the golf course, a correlation cannot be made with the facility name that was registered and the driver will not know what to do.
Furthermore, in a case where a place of interest such as a tourist spot is registered, an inconvenience arises when a plurality of locations reside in the same district or at the same address. Specifically, all of the identical addresses are registered in such case.
Thus, the conventional apparatus is such that when it is attempted to simplify location input by registering a desired location in advance using a memory function, information relating to a location recognized by a variety of content comes to be registered as limited date-and-time information or address information. As a consequence, this information becomes dissociated from information which the driver recognizes as relating to the location and is difficult to comprehend. Misunderstanding and erroneous recognition tend to result.
Further, when any desired location is entered to set a destination or transit point in a vehicular navigation system installed in an automotive vehicle, the following entry methods are utilized: Specifically, the forms of entry location are entry by code, entry by map coordinates, entry of registered location by retrieval according to genre and entry by telephone number. In entry of registered location by retrieval according to genre, such as address, station, government office, intersection, airport, port, police station, parking lot or hospital, etc., first the genre is selected, whereupon the names belonging to the genre branch out successively into the structure of a tree and are displayed in accordance with each selection. The names that are the object of selection in this case are displayed over several lines in the form of a list in the order of a fixed series of characters (character string) that has been determined in advance. Selection of a name is carried out using a prescribed position in the list as a selection window.
FIG. 1 is a diagram showing an example of a display in which a list in a conventional selection window is scrolled. This illustrates a case in which registration of a location is performed by input based upon address, by way of example. When an address is selected using a place-name index screen (not shown) for location registration, first the prefecture and principal cities are displayed on the screen in the selection window in the fixed character order. For example, when Tokyo and its 23 wards have been selected, Kuroda Ward is moved to the position of the selection window and displayed. The hiragana syllables "shi", "su", "se" and "ta" represent the first characters. The arrows on the left side are search scroll buttons and the arrows on the right side are line-feed scroll buttons. When a search scroll button is touched, the first character is moved to the top line, for example, in regular order together with the list "Shinjuku Ward", "Suginami Ward", . . . etc. When a line-feed scroll button is touched, the list is scrolled one line at a time.
In a case where scrolling is performed one line at a time in order to find a desired name on the screen thus displaying names in the selection window in the fixed character order, it is comparatively easy to set a target name in the prescribed window based upon a prediction from the continuous scrolling movement of the names. However, in a case where the list is scrolled based upon the first characters in the fixed character order, the scrolling of a target name subordinate to the first character becomes random in form. Consequently, when a target first character has entered the prescribed window, scrolling cannot be stopped at the proper timing. In other words, names subordinate to a first character may be many or few in a random manner. Accordingly, when the list is scrolled based upon the first character, there are instances where the next first character moves into the prescribed window owing to a time lag in the control system even if the scroll button is released after the target first character has entered the window. This means that it is necessary to back up by using the scroll button for the opposite direction. The result is poor operability.
Further, if such scrolling of the first characters is continuous rather than random with respect to the list of names, operability equivalent to that of scrolling one line at a time is obtained. However, scrolling to the target name would take too much time.